1. Technical Field
The present disclosure relates to a functionalized nanomaterial comprising bis(diarylphosphinomethyl) dopamine based ligands anchored to iron oxide nanoparticles. Additionally, the present disclosure relates to methods for producing the functionalized nanomaterial and its application to chelate catalytic metals and catalyze chemical transformations involving those catalytic metals including the hydroformylation of olefins to aldehydes.
2. Description of the Related Art
The “background” description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description which may not otherwise qualify as prior art at the time of filing, are neither expressly or impliedly admitted as prior art against the present invention.
Aldehydes can be converted into a number of useful chemicals via condensation, hydrogenation, amination, etc. The catalyzed hydroformylation reaction is of significant commercial importance in the production of aldehydes from aliphatic as well as substituted aromatic olefins via syngas-mediated reactions. Approximately 11 million metric tons of oxo chemicals are produced and consumed per year worldwide with an annual growth rate of 4%. [S. K. Sharma and R. V. Jasra, Catal. Today, 2015, 247, 70. —incorporated herein by reference in its entirety]. Homogeneous catalytic processes have been extensively used for the alkene to aldehyde conversion [C. Claver, P. Kalack, L. A. Oro, M. T. Pinillos and Cristina Tejel, Journal of molecular Catalysts, 1987, 43, 1; A. Orejon, C. Claver, L. A. Oro, A. Elduque and M. T. Pinillos, Journal of Molecular Catalysis A: Chemical 1998, 136, 279; A. B. Rivas, J. J. Pérez-Torrente, A. J. Pardey, A. M. Masdeu-Bultó, Montserrat Diéguez and Luis A. Oro, Journal of Molecular Catalysis A: Chemical 2009, 300, 121; J. Norinder, C. Rodrigues, A. Börner, Journal of Molecular Catalysis A: Chemical 2014, 391, 139; M. Jouffroy, R. Gramage-Doria, D. Armspach, D. Semeril, W. Oberhauser, D. Matt, and L. Toupet, Angew. Chem. Int. Ed. 2014, 53, 3937; L. C. Matsinha, S. F. Mapolie, and G. S. Smith, Dalton Trans., 2015, 44, 1240; P. Dydio, R. J. Detz, B. D. Bruin, and J. N. H. Reek, J. Am. Chem. Soc. 2014, 136, 8418; T. T. Adint and C. R. Landis, J. Am. Chem. Soc. 2014, 136, 7943; L. Wu, I. Fleischer, R. Jackstell, I. Profir, R. Franke, and Matthias Beller, J. Am. Chem. Soc. 2013, 135, 14306; and Z. Nairoukh, J. Blum, Journal of Molecular Catalysis A: Chemical 2012, 358, 129—each incorporated herein by reference in its entirety]. However, the challenges in separation are paramount and the cost of separation is prohibitively high in terms of the need to use fairly expensive chemicals and fairly large amounts of precious metals.
In the past two decades, great efforts have been devoted toward developing alternatives to homogeneous catalysis to minimize the separation cost and maximize the product purity. Heterogeneous catalysis offers the ease of separation and reusability. Moreover, it minimizes the use of environmentally toxic solvents needed in large quantities for separation and purification [V. Polshettiwar and R. S. Varma, Green Chem., 2010, 12, 743.—incorporated herein by reference in its entirety]. Most of the heterogeneous catalysts are supported on solids such as silica [V. Polshettiwar, B. Baruwati and R. S. Varma, Chem. Commun., 2009, 1837; K. Nozaki, Y. Itoi, F. Shibahara, E. Shirakawa, T. Ohta, H. Takaya and T. Hiyama, J. Am. Chem. Soc. 1998, 120, 4051; S. Ricken, P. W. Osinski, P. Eilbracht and R. Haag, J. Mol. Catal. A Chem. 2006, 257, 78; R. S. Varma, Pure Appl. Chem., 2013, 85, 1703; and A. R. McDonald, C. Muller, D. Vogt, G. P. M. van Klink and G. van Koten, Green Chem., 2008, 10, 424—each incorporated herein by reference in its entirety]. Silica is highly stable, robust and easy to functionalize; organic functional groups can be easily anchored via either covalent bonding or adsorption on the surface to provide catalytic centers [A. S. Kumar, M. A. Reddy, M. Knorn, O. Reiser, and B. Sreedhar, Eur. J. Org. Chem. 2013, 4674. —incorporated herein by reference in its entirety]. However, in most of the cases, a great number of catalytic sites are buried within the solid support, thereby resulting in a decrease in the overall reactivity. Leaching out of the catalyst by the cleavage of bonds between metal and ligand also hinders the ease of separation.
Due to their robustness and high surface area, nanoparticles have become favorable catalyst support systems [R. Abu-Reziq, H. Alper, D. Wang, and Michael L. Post, J. Am. Chem. Soc. 2013, 128, 5279; and J. P. K. Reynhardt, Y. Yang, A. Sayari and H. Alper, Adv. Synth. Catal. 2005, 347, 1379—each incorporated herein by reference in its entirety]; at nanoscale, the catalyst center may be more exposed to the reactant, thereby enhancing the activity. In this regard, superparamagnetic iron oxide nanoparticles (SPIONs) offer a promising research strategy to develop surface coated recyclable catalysts by anchoring homogeneous organic species (ligand or metal complexes) on the heterogeneous system, thus combining the advantages of both of the systems. In this context, a dendritic hydroformylation catalyst with excellent reactivity and selectivity attributes has recently been reported [R. Abu-Reziq, H. Alper, D. Wang, and Michael L. Post, J. Am. Chem. Soc. 2013, 128, 5279. —incorporated herein by reference in its entirety]. For these purposes, the chelating ligand, bis(diphenylphosphinomethyl) amine has proven itself for its interesting nature of coordination modes with different transition metals and its wide range of catalytic applications [T. T. Co and T.-J. Kim, Chem. Commun., 2006, 3537—incorporated herein by reference in its entirety].
In view of the forgoing, one object of the present disclosure is to provide novel functionalized nanomaterials comprising bisphosphinated dopamine (bpd) based ligands anchored on nanostructured magnetic nanoparticles. A further aim of the present disclosure is to provide an economical and robust process for synthesizing and characterizing the produced functionalized nanomaterials. An additional aim of the present disclosure is to provide applications of the functionalized nanomaterials as recyclable and thermally stable catalysts once chelated with a catalytic metal in a wide variety of chemical transformations such as the conversion of olefins to aldehydes by hydroformylation using rhodium as the catalytic metal center.